--- a/third_party/rapidyaml/rapidyaml-0.10.0.hpp
+++ b/third_party/rapidyaml/rapidyaml-0.10.0.hpp
@@ -614,6 +614,15 @@ C4_FOR_EACH(PRN_STRUCT_OFFSETS, a, b, c)
 #   endif
 #   define C4_BYTE_ORDER _C4EB
 
+#elif defined(__GNUC__) && defined(__SIZEOF_POINTER__) && defined(__BYTE_ORDER__)
+    /* generic GCC compatible fallback, e.g. alpha, hppa, m68k, sh */
+#   define C4_WORDSIZE __SIZEOF_POINTER__
+#   if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#       define C4_BYTE_ORDER _C4EB
+#   else
+#       define C4_BYTE_ORDER _C4EL
+#   endif
+
 #elif defined(SWIG)
 #   error "please define CPU architecture macros when compiling with swig"